Educational appliance



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Aug. 7, 1928.

Aug. 7, 1928. l 1,679,539

H. J. MULLER EDUCAT IONAL APPLIANCE Filed Sept. l, 1927 2 Sheets-Sheet 2w al ATTORNEf.

Patented ug. 7, 1928.

UNITED STATES HERMANN J. MULLER, OF AUSTIN TEXAS.

EDUCATIONAL APPLIANCE.

Application led September 1, 1927. Serial No. 216,818.

My present invention relates primarily to educational devices and isshown in a specific illustrative embodiment for demonstrating the`processes governing heredity 'and cell-division.

. It is an object of the invention to provide a simple, inexpensivedevice of the above type, which can be easily set and convenientlyactuated without `the exercise of skill or training, to clearlyillustrate or exemplify processes 'of heredity and cell-divisionheretofore comprehended with difficulty by the average biology student.

In the accompanying drawings in which is shown one of various possibleembodiments of the several features of the invention,

Fig. 1 is a plan view of the device showing the disks spread apart,

Fig. 2 is a view similar to Fig. 1,- showing the disks drawn together,

Fig. 3 is a rear plan view ofthe device, Fig. 4t is a transversesection' taken on line 1r-t of Fig. 3,A l

Fig. 5 is a perspective view on a larger scale showing one of thechromosomes,

Fig. Gis a sectional detail on a larger scale taken along line 6 6 ofFig. 4t, Fig. 7 is a fragmentary detail of a modified focal structure,

Fig. 8 is a sectional detail taken on line 8-8 of Fig. 7.k n n In thedrawings are shown a. pair of disks 10 and 11 of cardboard, celluloid orthel like, representing a pair of cells. Each of-tliese disks hasassociated therewith a plurality'of filaments or cords 12 representingthe spindle fibers. For the specific purpose of the present application,all ofthe cords, illus trativelyv six in number, of each disk, extendthrough a common focal part, in this embodiment, an eyelet 13 thereinnear the 'periphery of the disk. The cords 12 radiate from the focaleyelet 13 to holes or eyelets- 14 aligned along a chord symmetricalwitlirespect to the focal eyelet.

Both extremities of each of t-he Cords are attached to a common movable.anchoring or operating member, illustratively a bar -or stick 15 at theback of the disk. As shown, the extremities of the cords through thefocal eyelet 13 extend parallel as at 16 along* the back of the disk andare secured at an eye 16 at the middle of the, bar 15,.while the and areattached as at 17 at corresponding intervals along the length oftheanchor bar 15.

The two disks are of substantially identical construction, as shown,except that one of said disks hasa wide tongue 18 extending from thechorda-a and determined by a pair of parallel'slits 2()k in the disk,said tongue fitting intoV a corresponding slit 21 in the other disk.Slit 21 is closed at both ends, that is, it terminates between the endsof the corresponding chord. The two disksy are associated with eachother by securing the limb of each as by means of a hookl and eyeeonsti'uction 22 to the. companion disk., A backing disk 22 affixes thehook to the disk.

For illustrating the process of heredity, I

preferably provide a group of small blanks 23 of stiff paper, cardboard,Celluloid or the like, suitably colored and diversely shaped tokrepresent chromosomes of the different kinds and having suitable spotsor markings 24 thereon to represent the genes which determine thehereditary characteristics. Each of these elements 23preferably has adetachable fastener', such as a snap fastener element 25 by which it maybe releasably attached to a complementary fastener element 26 on thefilament.;

y To illustrate the opei'ation of cell-division,

`vchromosome pieces 23 will be selected to represent the characteristicsof the parent cell, each set of these elements being affixed by its snapfastener 25 to the fastener 26 on the filament 12, representing anassociated spindle fiber. v

The disks being brought to the position vso shown in Fig. 1, which canbe readily ef' fected by grasping the two anchoring bars 15 at the backsof the disks and drawing said bars apart, the exposed lengths of thefilaments `will be aligned as shown in Fig. 1, along the median line oraxis a-a of lthe cell, that is aboutv to divide. vThe chromo soines 23appear in pairs, illustratively six pairsthe twovmeinbersrof each pairrepresenting identical halves Vof one original chromosome. When thedisks1() and 11 are drawn apart to the utmost, as shown in Fig. 2, each ofthe chromosomes will be seen tov become grouped, in the single mass ornucleus M adjacent the centrosome or focus, illustrating the completionof cell-division. f

yIn this operation, the chromosome elements Awill lmove as riders withthe filaments to- Ward the focal eyelets 13 representing thecentrosomes, each group forming the nucleus N ot an offspring cell andhaving some of the chromosomes 23 and the corresponding genes 24.- oleach o'l the parent cells. As the cells draw apart, the furrovvs Adeepen as in nature, until the cells are entirely separated.

It will be obvious vthat by ag'ipropriate selection and grouping,various hereditary processes may be illustrated, including that ofreduction karyokinesis.

In Figs. 'Z and 8, the focal part is embodied as a cluster of'apertures, one for each spindle fiber. rlhe apertures 30 are stamped ina. sheet metal Washer 31 in -front of a hole 32 in the disk. f The metalWasher has tongues 33 clenched over the material of the disk as at 34..Thus, each -filament or spindle .fiber i2 has its distinct passage nea-rthe focus,

obviat-ing the need for waxed or silk iilaments which Would be requiredin the other embodiment, to reduce 'frictional interference between thefilaments in rubbing over each other.

The invention is not limited in its application to classroom charts ollarge dimension, but can readily be embodied in small or book-sizedimensions to be conveniently lodged for instance, Within a pocket inthe cover of a textbook on heredity. The appliance When removed from thepocket, may be manipulated by the student to exemplify the processesdescribed in the tent.

lt Will be understood that various mechanical details of the deviceshown, may be subject to modilication Within the scope o my invention,as claimed.

While the invention is shown in an application :tor illustrating` theprocesses of heredity or cell-division, for which purpose it has itspreferred utility, it Will be understood that the mechanical principlesdisclosed, may be embodied for the demonstration et phenomena,operations or systems of totally diiierent character.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is l. A device forillustrating mechanically the processes of cell division, comprising apair of cell members each having chromosome elements movablyassociated,therewith and connect-ing means between the cell elements,operativelyk connected to the chromosome element to Vcanse thelatter tomove relativev to each other when the coil members are moved toward oravvay from each other.V

2. A device for illustrating' mechanically the processes of-celldivision, comprisingl a pair of plate members, 'each having elongatedguides radiating from a common focus part and lsmaller elementsrepresenting chromosomes directed by the respective guides,v and meanstor'c'ausing said chromosomes to be ner/asso disks, chromosomeelementsmounted on the respective filaments and means operable from the back ofsaid disks to cause said chromosome elements to move toward or from theY median line at will along the lengths represented by the correspondingfilaments.

5. An article oi" the character described comprising a. pair of disks,means connectingl said disks to permit relative approach and limitedseparation thereof, smaller pieces mounted on the respective disks, andoperating members for moving said pieces, said operating members beingassociated With they connec ving means between said' disksl to causeindependent movement of said piecesas the disks are moved toward or fromeach other.

6. A device of the character described comprising a pair of interlittingdisks, filaments interconnecting said disks, each of said disks having adisplaceable anchoring member at the rear thereof for the filaments, theanchoring member of each disk being connected to they other disk,whereby the disks can be separate-d by drawing them apart and can becaused to approach by drawing apart said anchoring members at the rearof 'the device.

7. A device ot the character described, comprising a pair of plates, onehaving a Wide tongue extending into a corresponding slit in the other,each plate having a series ot filaments extending` along the irontthereof through holes therein, a movable anchoring bar at. the rear ofcach plate to which are ai'xed both ext 1emities of the filaments on theplate, each plate being secured to the anchoring bar of the companionplate, Whereby the plates may be 'drawn apart by hand and may be drawntoward eachother by drawing apart said anchoring bars. y

8. The combination set forth in claim 7 in which smaller pieces areailixed to the respective filaments, whereby said pieces Will travelalong the respective plates with the movement of the iilaments in theapproach and separation ot the plates.

9. An article of the character described,V

comprising a pair o1c disks, one of said disks having a 'tonguedetermined by a pair of slits therein and litting into a correspondingslit having its extremities between the ends of the corresponding chordof the other' disk, each of said disks having a set of filamentsradiating from a common focal part in the disk and extending throughaligned holes parallel to the chord of intersection of said disks, eachof said disks having an anchor bar at the rear thereof to which both eX-trcmities of each of the. corresponding filaments are attached, andmeans attaching each of the disks to the anchor bar of the other disk.

l0. The combination set forth in claim 9 in which smaller pieces areattached to the respective filaments so that in the approach orseparation of the disks, the` lsmaller pieces will perform movementsrelative to the disks.

ll. ln an article of the character described, a supporting plate, aplurality of filaments extendingthrough apertures therein, a commonanchoring element at the reverse face of said disk to which the oppositeextremities of all of said filaments are attached, and riders mounted onsaid filaments to travel lengthwise thereof as the common anchor at therear is moved backward and forward.

l2. In an article of the character described, a circular supportingplate having a plurality7 of eyelets aligned along one chord thereof andhaving a reinforce structure near the periphery, symmetrical withrespect to said chord, said re-enforce structure having aperturestherein equal in number to said eyelets.

13. An article of the character described, comprising a disk, a focusstructure comprising a metal wash-er having a plurality of smallapertures therein, means securing said washer over an aperture in saiddisk, a plurality of eyelets arranged along'a chord symmetrical withrespect to said focus structure, a plurality of filaments radiating fromthe various apertures in the focus structure to the various eyelets, andmeans to advance said filaments in synchronism with respect to saidapertures. n

Signed at New York city in the county of New York and State of New Yorkthis 29th day of August, A. D. 1927.

HERMANN J. MULLER.

